Bore size question

[raul arrese]

Does anyone know of a chart or a place where I can find the sizes you bore in the case and heads depending on what size jugs you use ?? I have some heads here that I measured up at around 98 mm so im guessing they are for 94's ???

[Marc]

98mm is the nominal diameter for late 90.5s, "classic" 92s, and possibly NPR 90s (not verified yet). 94mm Type I cylinders take a 101.1 diameter head bore.

http://img.photobucket.com/albums/v481/ ... nsions.jpg



NOTE - this chart is a "work in progress" that hasn't made much progress lately. I encourage any comments that will help it along.

[raul arrese]

98mm is the nominal diameter for late 90.5s, "classic" 92s, and possibly NPR 90s (not verified yet). 94mm Type I cylinders take a 101.1 diameter head bore.

http://img.photobucket.com/albums/v481/ ... nsions.jpg



NOTE - this chart is a "work in progress" that hasn't made much progress lately. I encourage any comments that will help it along.

thanks , nice chart

[Phil69]

I personally wouldn't go for 94mm barrels and pistons as there is far less fin area and as such the engine could run on the hot side over long journeys.
This is just a personal opinion.

[Marc]

Old-school 92s were considered the maximum possible bore within the confines of the 10mm headstud circle that existed at the time - and they were far too thin for longevity, which is why thickwall 90.5s were introduced.
When 8mm headstuds became the norm, the envelope was again pushed to bring us 94s. They might have even gone further were it not for hitting daylight when the cylinder heads were hogged out to accommodate them.
What I find ironic is that even though 94mm cylinder walls are a scant .006" thicker than those of slip-in 87s, most of the proponents of 94s are the same folks who admonish us that 87s are too thin...it should be obvious that at the larger bore diameter there'll be even more trouble with the cylinder retaining shape through thermal cycling, so whatever problems 87s have aren't likely to be fixed with .006" more iron.
A few years back AA introduced thickwall 92s (history repeats) which finally offer a generous cylinderwall thickness - one of the thickest available of any off-the-shelf barrels. Unfortunately they still have the same lower register as 94s, but if one wants to avoid removing that much material from the case there's the option of having their lower spigots turned down to the 90.5/classic 92 diameter. Oddly, this operation often causes the inside diameter near the bottom to constrict slightly, so I advise having them Tru-honed afterwards.

[raul arrese]

I personally wouldn't go for 94mm barrels and pistons as there is far less fin area and as such the engine could run on the hot side over long journeys.
This is just a personal opinion.

My motor runs on E-85 so im kinda the opposite , i have a hard time keeping it warm ... i purchased some AA 94 's and my case is 8mm so im gonna give it a try : )

[Phil69]

I personally wouldn't go for 94mm barrels and pistons as there is far less fin area and as such the engine could run on the hot side over long journeys.
This is just a personal opinion.

My motor runs on E-85 so im kinda the opposite , i have a hard time keeping it warm ... i purchased some AA 94 's and my case is 8mm so im gonna give it a try : )

AA quality is top notch from what I have been told by engine builders. I am unfamiliar with E-85 as a fuel (unless it is Ethanol race fuel).

[Marc]

....I am unfamiliar with E-85 as a fuel (unless it is Ethanol race fuel).

Corn-likker gas that's subsidized by your tax dollar, and contributing to the escalation of the price of a whole lot of grocery items - especially Beef/Pork/Poultry that use corn as feed. Not even environmentally friendly since it takes as many BTUs of energy to distill a gallon of ethanol as are contained in a gallon of ethanol. Production, distillation, even transportation of ethanol is all government-subsidized - big agribiz is the only winner (but that's what they paid for when they bought off the politicians who passed these bullsh*t laws, so it comes as no surprise)

[Phil69]

....I am unfamiliar with E-85 as a fuel (unless it is Ethanol race fuel).

Corn-likker gas that's subsidized by your tax dollar, and contributing to the escalation of the price of a whole lot of grocery items - especially Beef/Pork/Poultry that use corn as feed. Not even environmentally friendly since it takes as many BTUs of energy to distill a gallon of ethanol as are contained in a gallon of ethanol. Production, distillation, even transportation of ethanol is all government-subsidized - big agribiz is the only winner (but that's what they paid for when they bought off the politicians who passed these bullsh*t laws, so it comes as no surprise)

What sort of octane rating does this fuel have?
We run 95,98 and 99 octane E-5 (shortly to become E-10) in the UK.

[raul arrese]

....I am unfamiliar with E-85 as a fuel (unless it is Ethanol race fuel).

Corn-likker gas that's subsidized by your tax dollar, and contributing to the escalation of the price of a whole lot of grocery items - especially Beef/Pork/Poultry that use corn as feed. Not even environmentally friendly since it takes as many BTUs of energy to distill a gallon of ethanol as are contained in a gallon of ethanol. Production, distillation, even transportation of ethanol is all government-subsidized - big agribiz is the only winner (but that's what they paid for when they bought off the politicians who passed these bullsh*t laws, so it comes as no surprise)

What sort of octane rating does this fuel have?
We run 95,98 and 99 octane E-5 (shortly to become E-10) in the UK.

its 105 octane

[Marc]

Be cautious when comparing octane rating numbers between the U.K. and the "colonies" - there's about a 4-point difference between the rating systems used.
viewtopic.php?f=11&t=142918

As for "105 octane", in your dreams..."The Renewable Fuels Foundation states in its Changes in Gasoline IV manual, "There is no requirement to post octane on an E85 dispenser. If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2. These calculations have been confirmed by actual-octane engine tests." [10]

Examples of this mis-citation can be found at the Iowa Renewable Fuels Association titled "E85 Facts"[11] which cites a range of 100-105, and a document at the Texas State Energy Conservation Office titled "Ethanol",[12] which cites a 113 rating."
http://en.wikipedia.org/wiki/E85